Potassium Hydroxide → Benzylmalonic acid

Reaktionsgleichung

C(C1N(CC2C=CC=CC=2Cl)C([C:10]([CH2:21][C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=2)([C:16]([O:18]CC)=[O:17])[C:11]([O:13]CC)=[O:12])=CN=1)CCC.[OH-].[K+]>C(O)C.O>[CH2:21]([CH:10]([C:11]([OH:13])=[O:12])[C:16]([OH:18])=[O:17])[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1

Komponenten

Versuchsvorschrift

A solution of diethyl [2-n-butyl-1-{(2-chlorophenyl)methyl}-1H-imidazol-5-yl]-2-benzyl-malonate [Example 8(iii)] (5.54 g, 0.0108 mol) in ethanol (75 mL) was treated all at once with a solution of potassium hydroxide (3.65 g, 0.065 mol) in water (50 mL). The resulting mixture was stirred at room temperature for 24 hours, then refluxed for 3 hours. The ethanol was evaporated, water was added to the aqueous product, and the basic solution was extracted with diethyl ether. The aqueous layer was acidified to pH 4 with hydrochloric acid and the product was extracted into ethyl acetate. The dried, concentrated product was crystallized twice from ethyl acetate to give 0.6 g of 2-n-butyl-1-{(2-chlorophenyl)methyl}-1H-imidazol-5-yl]-2-benzyl-malonic acid; mp 165°-166° C.(d). The filtrates from the crystallizations (4.9 g) consisted of additional malonic acid, the propanoic acid derivative and the mono ethyl ester malonate derivative. These are converted to [ 2-n-butyl-1-{(2-chlorophenyl)methyl}-1H-imidazol-5-yl]-2-benzylpropanoic acid by the method described previously.